吡喃酮型花色苷衍生物的制备、光谱特性及抗氧化活性研究

Preparation,Spectral Properties and Antioxidant Activities of Pyranone-Anthocyanin Derivative(Oxovitisin)

吡喃酮型花色苷衍生物是一类具有非氧鎓离子结构和内酯型吡喃环结构的新型多酚类化合物。本研究以植物花色苷为原料,通过羧基吡喃花色苷形成及微氧化等两步反应法,结合柱色谱分离纯化技术,制备高纯度的吡喃酮花色苷衍生物A(Oxovitisin A)标准品;高效液相色谱-光电二极管阵列检测器-串联质谱法(HPLC-DAD-ESI-MS/MS)分析鉴定出纯化后反应产物Oxovitisin A的纯度达99%以上。利用荧光光谱仪、紫外可见光谱仪及超微弱化学发光光谱仪研究了Oxovitisin A及其前体物质花色苷(锦葵素-3-葡萄糖苷,Mv-3-gluc)与羧基吡喃花色苷A(Vitisin A))的光谱特性、色泽稳定性及抗氧化活性。结果表明:Oxovitisin A在440nm激发波长下有最大荧光峰,最大发射波长490nm,而具有氧鎓离子结构的两种前体物质无荧光特性。紫外光谱结合LAB色泽空间表征参数显示Oxovitisin A在不同pH值条件下具有不同的结构稳定性和色泽稳定性。Mv-3-gluc,VitisinA和Oxovitisin A在不同体系中均表现出良好的抗氧化活性,清除超氧阴离子自由基的IC50值分别为71.4,30.7和19μg·mL-1(抗坏血酸28μg·mL-1),清除羟自由基的IC50值分别为1.68,3.524,2.854μg·mL-1(抗坏血酸8.441μg·mL-1),对双氧水清除率的IC50值分别为1.311,0.4098和0.288μg·mL-1(抗坏血酸3.265μg·mL-1),表明Oxovitisin A清除自由基和抗氧化的能力均高于反应前体物Mv-3-gluc和VitisinA及抗坏血酸。

A novel polyphenolic compound,named Oxovitisin,with unique lactone pyranone ring and non-oxonium structures was prepared.In this paper,Oxovitisin A was synthesized with two-step reactions in micro-oxygenation system using carboxypyranoanthocyanins formed from pyruvic acid and anthocyanins.The fraction of Oxovitisin A was isolated by a combination of several chromatographic techniques and identified with HPLC-DAD-EI-MS/MS.The results showed that the purity of Oxovitisin A could reach more than 99%after purification.The study investigated the florescence spectra of Oxovitisin A,the effect of different pH value on UV feature and color parameters.The antioxidant activities of Oxovitisin A were evaluated by using a BPCL Ultra-weak luminescence analyzer in vitro,which were compared with that of Vitisin A,Mv-3-gluc and Vitamin C.The results revealed that Oxovitisin A had an obvious fluorescence peaks under the excitation wavelength of 440 nm,but no intensity of florescence was detected on Vitisin A and Mv-3-gluc.Analysis with UV spectroscopy and color parameter variations method indicated that Oxovitisin A had a higher structural and color stability.All four compounds（Oxovitisin A,Vitisin A,Mv-3-gluc,Vitamin C）showed strong antioxidant activity in scavenging O-2（IC50of 71.4,30.7,19,28μg·mL-1,respectively）,·OH（1.68,3.524,2.854,8.441μg·mL-1,respectively）and H2O2（1.311,0.409 8,0.288,3.265μg·mL-1,respectively）.However,Oxovitisin A showed the highest antioxidant ability in scavenging free radical compared with Vitisin A,Mv-3-gluc and Vitamin C.